DO NOT LAND: Disable rAF prioritization

components/scheduler/renderer/renderer_scheduler_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/scheduler/renderer/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 679 matching lines @@
         // What we really want to do is priorize loading tasks, but that doesn't
         // seem to be safe. Instead we do that by proxy by deprioritizing
         // compositor tasks. This should be safe since we've already gone to the
         // pain of fixing ordering issues with them.
         new_policy.compositor_queue_policy.priority =
             TaskQueue::BEST_EFFORT_PRIORITY;
       }
       break;
 
     case UseCase::SYNCHRONIZED_GESTURE:
-      new_policy.compositor_queue_policy.priority = TaskQueue::HIGH_PRIORITY;
+      //new_policy.compositor_queue_policy.priority = TaskQueue::HIGH_PRIORITY;
       if (touchstart_expected_soon) {
         expensive_task_policy = ExpensiveTaskPolicy::BLOCK;
       } else {
         expensive_task_policy = ExpensiveTaskPolicy::THROTTLE;
       }
       break;
 
     case UseCase::MAIN_THREAD_GESTURE:
       // In main thread gestures we don't have perfect knowledge about which
       // things we should be prioritizing, so we don't attempt to block
       // expensive tasks because we don't know whether they were integral to the
       // page's functionality or not.
-      new_policy.compositor_queue_policy.priority = TaskQueue::HIGH_PRIORITY;
+      //new_policy.compositor_queue_policy.priority = TaskQueue::HIGH_PRIORITY;
       break;
 
     case UseCase::TOUCHSTART:
       new_policy.compositor_queue_policy.priority = TaskQueue::HIGH_PRIORITY;
       new_policy.loading_queue_policy.is_enabled = false;
       new_policy.timer_queue_policy.is_enabled = false;
       // NOTE this is a nop due to the above.
       expensive_task_policy = ExpensiveTaskPolicy::BLOCK;
       break;
 
@@ skipping 521 matching lines @@
     }
     MainThreadOnly().have_reported_blocking_intervention_since_navigation =
         true;
     BroadcastConsoleWarning(
         "Deferred long-running timer task(s) to improve scrolling smoothness. "
         "See crbug.com/574343.");
   }
 }
 
 }  // namespace scheduler